There exist a number of arrangements for detecting the occupancy of a seat, which function on the basis of any of the following methods:
Mats in the seat area with pressure detection PA1 Pressure detection at seat frame PA1 Making use of a high-frequency attenuation PA1 Making use of the change in capacitance
These above systems have the disadvantages that, they cannot sufficiently distinguish the type of seat occupancy and they are not capable of detecting the presence of such objects as child seats.